A new study from the University of Hong Kong found that no Hong Kong residents tested in the early stages of Covid-19 displayed immunity while only 4% of tested HK returnees from Hubei province carried antibodies to the coronavirus.
The research team led by HKU microbiologist Professor Yuen Kwok-yung, collected serum samples from more than 1,900 Hongkongers between April 2018 and February this year before the first reported case in the city. None were found to have contained antibodies against the coronavirus.
The team also collected blood samples from 452 Hongkongers returning from Hubei province in early March, and found just 17 individuals (3.8%) carried antibodies against the coronavirus.
The team explained that applying the antibody positivity rate to the whole province, which had a population of 59 million, there should be 2.2 million people infected. As of the end of March, there were only about 67,800 lab-confirmed cases in Hubei.
The research was published in the scientific journal The Lancet Microbe last week.
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